A study on the development and application of program for planetary gear design considering planetary gear noise and efficiency

2021 ◽  
Vol 263 (5) ◽  
pp. 1516-1526
Author(s):  
Hyun Ku Lee ◽  
Moo Suk Kim ◽  
Sa Man Hong ◽  
Dong Kyu Yoo ◽  
Ahmet Kahraman ◽  
...  
Keyword(s):  
Input Parameter ◽  
Automatic Transmission ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Design Stage ◽  
Concept Design ◽  
Mechanical Loss ◽  
Gear Noise ◽  
Gear Design ◽  
Planetary Gear Sets

In general, gear mechanical loss is associated with the friction of the lubricating contact surface of the gear and bearing that transmit the power, and a no-load spin loss which is load independent occurs due to gear rotation and the interaction of the bearing component with the lubricating element. In order to minimize planetary gear loss, it is desirable to design by checking the efficiency at the concept design stage. However, a design technique that considers the noise and efficiency of a planetary gear set simultaneously has not been achieved so far. In this paper, a program called 'pRMC with EHL' to check together the efficiency and noise that affected by gear specifications has been developed. By using developed program, planetary gear sets specifications have been designed. And through the experimental evaluation, automatic transmission efficiency could be reduced by 0.3% in combination fuel consumption mode and the planetary gear vibration could be also reduced by 10 dB than former design. Through this designing verification and input parameter correlation, a new planetary gear set designing process has been come up with successfully at the concept design stage.

scholarly journals Dynamics and efficiency of planetary gear sets for hybrid powertrains

2015 ◽  
Vol 230 (7-8) ◽  
pp. 1359-1368 ◽  
Author(s):  
M Mohammadpour ◽  
S Theodossiades ◽  
H Rahnejat
Keyword(s):  
Electric Motor ◽  
Hybrid Electric Vehicle ◽  
Combustion Engine ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Drive Mode ◽  
Planetary Gear Sets ◽  
Hybrid Electric ◽  
Noise Vibration ◽  
Six Degree Of Freedom

The paper presents a tribo-dynamic model for planetary gear sets of hybrid-electric-vehicle configurations. The model comprises a six degree-of-freedom torsional multi-body dynamic system, as well as a tribological contact model in order to evaluate the lubricant film thickness, friction and efficiency of the meshing gear teeth contacts. The tribological model takes into account the non-Newtonian, thermal-mixed elastohydrodynamic regime of lubrication. Analysis is performed for a hybrid electric C-segment vehicle. The simulated conditions correspond to cases of power supplied by either the engine or the electric motor. The results illustrate that in the electric motor drive mode, improved noise, vibration and harshness refinement would be expected, whereas better transmission efficiency is achieved in the internal combustion engine drive mode.

Fuzzy Reliablity Optimization Design of Two Stage Planetary Gear System by Genetic Algorithm Based on Predatory Search Strategy

2011 ◽  
Vol 403-408 ◽  
pp. 743-747 ◽  
Author(s):  
Chun Guang Wang
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Reliability Analysis ◽  
Optimization Design ◽  
Search Strategy ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Fuzzy Reliability ◽  
Two Stage ◽  
Planetary Gear Sets

Fuzzy reliability analysis is regared as the theoretical basis. It takes the minimum volume and the maximum transmission efficiency as objective function．Then the mathematical model of fuzzy reliability optimal design on two stage planetary gear sets is set up. Genetic algorithm based on predatory search strategy is used to solve the fuzzy reliability mathematical model. Examples of calculation shows that the volume is decrease by 15%. The results imply the fuzzy reliability analysis is more scientific and reasonable in designing two stage planetary gear sets by using fuzzy reliability analysis.

A Research for the Planetary Gear Noise Development in FF 6th Speed Automatic Transmission

2011 ◽  
Author(s):  
Hyun-Ku Lee ◽  
Koo-Tae Kang ◽  
Moo-Suk Kim ◽  
Jin-Wook Hur
Keyword(s):  
Gear Tooth ◽  
Automatic Transmission ◽  
Planetary Gear ◽  
The Sun ◽  
Noise Levels ◽  
Noise Sources ◽  
Valve Body ◽  
Gear Noise ◽  
Radiated Noise ◽  
Transfer Path

In order to improve the planetary gear noise of the new developed 6th speed automatic transmission, it needs to understand noise mechanism. Basically, many transmission’s components have an effect on the gear noise. In this paper, planetary gear noise sources which are influenced by gear tooth shapes and backlash among the gears, position of pinion gears, and misalignment of the sun gear are studied and experimented. Also, transfer-path likewise one-way clutch contacted between the carrier and case, and valve-body covers are also researched to reduce the transferred vibration and radiated noise levels. After developing the planetary gear noise, its evaluation specification is adapted to EOL (end of line) equipment to check the transmission’s noise quality in the factory.

scholarly journals Investigation of the Influences of Thrust Loads Resulted by Helix Angle Directions of Planetary Gear Sets on Bearing Power Losses in Automotive Planetary Gear Trains

2021 ◽  
Vol 11 (19) ◽  
pp. 8827
Author(s):  
Hyun Sik Kwon
Keyword(s):  
Power Loss ◽  
Fuel Efficiency ◽  
Automatic Transmission ◽  
Reducing Power ◽  
Planetary Gear ◽  
Helix Angle ◽  
Transmission Model ◽  
Power Losses ◽  
Loss Analysis ◽  
Planetary Gear Sets

In the recent automotive industries, automotive technologies for improving fuel efficiency have focused on the developments of reducing power losses in a transmission. As a well-developed and conventional power transmitting system, an automatic transmission is still widely used in many automotive vehicles. The automatic transmission is co-axially designed with several planetary gear sets and other mechanical parts. The co-axial arrangements and gear helix angles make the transmission necessarily include bearings for supporting loads and allowing relative rotations. In this study, the influences of thrust loads yielded by helix angle directions of planetary gear sets on bearing power losses are presented by performing the structural and power loss analysis. Bearing power losses consist of mechanical and spin power losses. For calculating thrust loads and bearing rotations, a complete transmission model is constructed by using an example structure, and structural analysis is performed for the combinations of helix angle directions of the gear sets. Finally, bearing power losses are computed by using the bearing power loss model, and the results of the entire combinations of helix angle directions are discussed.

A Generalized Kinematics and Power Flow Analysis Methodology for Automatic Transmission Gear Trains

2003 ◽  
Author(s):  
A. Kahraman ◽  
K. Kienzle ◽  
D. M. Zini
Keyword(s):  
Power Flow ◽  
Search Algorithm ◽  
Gear Tooth ◽  
Automatic Transmission ◽  
Flow Analysis ◽  
Planetary Gear ◽  
Gear Train ◽  
Power Flow Analysis ◽  
Planetary Gear Sets ◽  
Transmission Gear

A generalized formulation for analyzing speeds and forces of the gear components of planetary automatic transmissions is proposed. The formulation is capable of analyzing any typical one-degree-of-freedom automatic transmission gear train containing any number of simple, compound or complex-compound planetary gear sets. It consists of three components: a kinematic analysis formulation, a gear ratio and kinematic configuration search algorithm, and a power flow analysis formulation. The kinematics module computes rotational speeds of gears and carriers. Given the type and number of planetary gear sets, the search module determines all possible kinematic configurations and gear tooth count combinations that result in a required set of gear ratios while eliminating all kinematic redundancies and unfavorable clutching sequences. The third component, the power-flow analysis formulation, performs a complete static force (power flow) analysis to determine all gear and bearing forces, and clutch and connection torque values. A five-speed transmission example is considered to highlight the capabilities of the proposed formulation.

scholarly journals Effect of mesh phasing on the transmission efficiency and dynamic performance of wheel hub planetary gear sets

2017 ◽  
Vol 232 (19) ◽  
pp. 3469-3481 ◽  
Author(s):  
Ehsan Fatourehchi ◽  
Mahdi Mohammadpour ◽  
Paul D King ◽  
Homer Rahnejat ◽  
Gareth Trimmer ◽  
...  
Keyword(s):  
Dynamic Performance ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Gear Teeth ◽  
Design Attributes ◽  
Frictional Performance ◽  
Planetary Gear Sets ◽  
Noise Vibration ◽  
New Generation ◽  
Mesh Phasing

Transmission efficiency and refinement of planetary wheel hub gearing system are key design attributes for heavy and off-highway vehicles. Reduction of power loss, directly leading to the development of new generation ECO-axles requires analysis of gear contacting conditions for lubricated conjunctions to determine frictional performance. This is also affected by gear dynamics, which is a prerequisite for assessment of noise, vibration and harshness performance. Therefore, a combined tribo-dynamic analysis is essential. There is a dearth of such holistic analysis, particularly for the case of wheel hub planetary systems. The paper presents such an analysis, which has not hitherto been reported in literature. The inexorable interplay of transmission efficiency and noise, vibration and harshness refinement is demonstrated. The key attributes of noise, vibration and harshness refinement and transmission efficiency can pose contrary requirements and near-optimal conditions can be highlighted by mesh phasing of gearing contacts, thus alleviating the need for more complex gear teeth modifications entailing prohibitive manufacturing costs.

Influence of Design Parameters on Mechanical Power Losses of Planetary Gear Sets

2015 ◽  
Author(s):  
H. S. Kwon ◽  
A. Kahraman
Keyword(s):  
Mechanical Load ◽  
Search Algorithm ◽  
Film Formation ◽  
Planetary Gear ◽  
Design Parameters ◽  
Power Losses ◽  
Gear Design ◽  
Gear Mesh ◽  
Profile Correction ◽  
Planetary Gear Sets

Mechanical (load-dependent) power losses of a planetary gear set occurs primarily along its lubricated rolling-sliding interfaces at the external and internal gear meshes, and planet bearings. The gear mesh originated portion of these losses are influenced by all key gear parameter, tooth profile correction and other parameters dictating the fluid film formation. In this study, a systematic planetary gear design search algorithm is combined with an efficiency formulation to (i) quantify the sensitivity of gear mesh mechanical losses of planetary gear sets to the basic gear design parameters and (ii) investigate the compromise that must take place between the mechanical efficiency and other functional attributes associated with durability and noise performance of the gear set. An example design study is presented at the end to demonstrate both of these points.

Sign in / Sign up

Export Citation Format

Share Document